Acute exercise-induced changes in basal VLDL-triglyceride kinetics leading to hypotriglyceridemia manifest more readily after resistance than endurance exercise
Resistance training is considered less effective than endurance training in lowering plasma triglyceride (TG) concentrations. Acutely, however, a single bout of strenuous exercise, whether endurance or resistance, increases the efficiency of very low-density lipoprotein (VLDL)-TG removal from the circulation and leads to hypotriglyceridemia. The comparative effects of these two types of exercise on VLDL-TG metabolism are not known. We therefore examined basal VLDL-TG kinetics by using stable isotope labeled tracers in 7 healthy, non-obese, untrained young men in the post-absorptive state, the morning after a single 90-min bout of either low-intensity endurance exercise (~30% of peak oxygen consumption) or high-intensity resistance exercise (3 sets of 10 repetitions for 12 exercises at 80% of peak torque production), matched for total energy expenditure (~400 kcal), or an equivalent period of rest on the preceding afternoon. Compared with rest, resistance exercise lowered fasting plasma VLDL-TG concentration by -28±10% (P=0.034), increased VLDL-TG plasma clearance rate by 30±8% (P=0.003), and shortened the mean residence time (MRT) of VLDL-TG in the circulation by -36±11 min (P=0.016), whereas endurance exercise had no effect (all P>0.05). Basal VLDL-TG plasma clearance rate was greater (P=0.003) and VLDL-TG MRT was shorter (P=0.012) the morning after resistance than endurance exercise. We conclude that, for the same total energy expenditure, resistance exercise is more potent than endurance exercise in eliciting changes in VLDL-TG metabolism that have been linked with hypotriglyceridemia, and should thus be considered as an alternative to or in addition to endurance exercise for the control of plasma TG concentrations.